CloudSim

virtualization

CloudSim is a free of cost framework which was developed by CLOUDS ( Cloud Computing and Distributed Systems) Lab and is fully written in JAVA.

CloudSim is an open-source framework, which is used to simulate cloud computing infrastructure and services. It is developed by the CLOUDS Lab organization and is written entirely in Java. It is used for modelling and simulating a cloud computing environment as a means for evaluating a hypothesis prior to software development in order to reproduce tests and results.
For example, if you were to deploy an application or a website on the cloud and wanted to test the services and load that your product can handle and also tune its performance to overcome bottlenecks before risking deployment, then such evaluations could be performed by simply coding a simulation of that environment with the help of various flexible and scalable classes provided by the CloudSim package, free of cost.

Following are the benefits of CloudSim

1. No capital investment involved. With a simulation tool like CloudSim there is no installation or maintenance cost.
2. Easy to use and Scalable. You can change the requirements such as adding or deleting resources by changing just a few lines of code.
3. Risks can be evaluated at an earlier stage. In Cloud Computing utilization of real testbeds limits the experiments to the scale of the testbed and makes the reproduction of results an extremely difficult undertaking. With simulation, you can test your product against test cases and resolve issues before actual deployment without any limitations.
4. No need for try-and-error approaches. Instead of relying on theoretical and imprecise evaluations which can lead to inefficient service performance and revenue generation, you can test your services in a repeatable and controlled environment free of cost with CloudSim.

Features of CloudSim

1. Open source and free of cost, so it favours researchers/developers working in the field.
2. Easy to download and set-up.
3. It is more generalized and extensible to support modelling and experimentation.
4. Does not require any high-specs computer to work on.
5. Provides pre-defined allocation policies and utilization models for managing resources, and allows implementation of user-defined algorithms as well.
6. The documentation provides pre-coded examples for new developers to get familiar with the basic classes and functions.
7. Tackle bottlenecks before deployment to reduce risk, lower costs, increase performance, and raise revenue.

Enhanced Features

CloudSim provides support for simulation and modelling of:
1. Large scale virtualized Datacenters, servers and hosts.
2. Customizable policies for provisioning host to virtual machines.
3. Energy-aware computational resources.
4. Application containers and federated clouds (joining and management of multiple public clouds).
5. Datacenter network topologies and message-passing applications.
6. Dynamic insertion of simulation entities with stop and resume of simulation.
7. User-defined allocation and provisioning policies.